Return bend housing



Aug. 6, 1935.

F. E. KEY

RETURN BEND HOUSING Filed Aug. 21, 1929 2 Sheets-Sheet 1 "AW [M70]? R N \Qu mm Aug. 6, 1935.

I F. E. KEY

RETURN BEND HOUSING Filed Aug. 21, 1929 2 Sheets-Shet 2 PM... Aug. 6, 1935' 2,010,571

UNITED STATES PATENT OFFICE-.1

RETURN BEND HOUSING Frederick E. Key, East St. Louis, 111., assignor to Key Boiler Equipment 00., East St. Louis, 111., a corporation of Missouri Application August 21, 1929, Serial No. 387,346

8 Claims. (01. ass-2o) This invention relates to return bend housings, cent ends of adjacent tubes and having connection and has special reference to housings and assowith the return bend of the device. ciated parts for connecting and forming satis- Fig. 4 is an inner end elevation of one of the iactorily leak-proof communication between adhousing members. 5 jacent tubes. Fig. 5 is a cross sectional view of one of the I Objects of. the invention are to provide means housing members on the line 55 of Fig. 1. for connecting and providing communication be- Fig. 6 is a plan view of a tie member mounted tween adjacent tubes and comprising sleeves or in connection with the tubes with which the prestubular elements secured to the ends of the tubes ent invention is connected. 10 in cooperative relationship in such a way that In the embodiment of. the invention shown, a 10 they cannot twist or move laterally relatively sleeve or tubular element '1 is connected with an to each other to any substantial extent but are end of each tube that is to be connected with an capable of relative longitudinal movement as readjacent end of an adjacent tube. One of these quired to provide tolerance and compensate for sleeves I is provided with a laterally extended ear certain inequalities in the associated parts of the or lug 8 located at the side of a similar laterally 15 structure, or inequalities in the arrangement or extended lug 9 in connection with the cooperating location of the ends of the tubes; to provide sleeve. In the specific construction shown (Figs. means for holding a return bend in cooperative 2 and 3), each sleeve 1 has laterally extended relationship with said sleeves or tubular elements ears or lugs 8 and 9, one of these ears or lugs by holding devices, including housing members on each sleeve extending between and in close 20 engaging and partially or completely enclosing contact with the ears or lugs on the other. This said sleeves or tubular elements; to provide a constitutes an embodiment of means for interstructure of this type and arrangement permitlocking the two sleeves and preventing substantial ting said sleeves or tubular elements and the retwisting or lateral movement of either sleeve with turn bend to be made from the same metal, or respect to the other. Aiter assembly, the ears or 25 from metals having approximately the same 00- lugs 8 and 9 lie side by side, and have slots ll eflicient of expansion, and the housing members in approximate alinement. A bolt ll extends to be made from a difierent and less expensive through the Slots and prevents pa on o metal; and to provide a novel and eilicient cothe P Sleeves cfllmwted y- Since t operative relationship of the housing members Sl ts II are longer than the diameter of the bolt 30 with the remaining elements of the device, wheree t ves e pable of relative longiby the duration of satisfactory use and eiiicient tudinal movement as required to P e U0 functioning of this device is extended much longer ance and compe r Certain qua s in than in the case of. many devices now in general associated Parts Of the Structure, q a t in the arrangement or location of the ends or the 35 Another object of the invention is to provide an es. improved return bend housing and cooperating The outer end or each sleeve 1 is formed with members functioning efliciently to maintain ima tapered bore l2, which receives, and the wall pervious and leak-proof joints with the connected of which constitutes, a joint forming seat for the tubes indefinitely and irrespective of the wide vatapered end B of & flP o a cuate tubular 40 riations in temperature, thus greatly reducing the return bend pp P t ons of the return m and th hazards n id t t th use of thi bend ll are provided with shoulders l5, each invention in connection with oil stills and other havin in its ut side a recess l6 iv n the mechanisms. abutting end ll of a securing set screw I8. The Various other objects and advantages of thi set screws l8 are screwed through threaded holes 45 invention should be apparent from the following n Plates l9 engag d with the adjacent ends of description, reference being made to the annexed respective housing members 20. The outer end drawings, in which--- of each housing member 20 is arcuate or approxi- Fig. 1 is a view with parts in section and other mately U-shaped in cross section and is formed parts in side elevation illustrating the invention with an inwardly extended flange 2| against 50 in connection with adjacent tubes. which an abutting portion 22 of the cooperating Fig. 2 is a sectional view approximately on the plate I! engages. The housing members 20 are line 2-2 of Fig. 1. also provided with openings 23 into which project Fig. 3 is an end plan view of the sleeves or tuparts 24 formed on the plates l9. This construcbular elements adapted to be attached to adiation, comprising the parts 24 extending into the openings 23, constitutes an interlock to prevent the plates. l9 from turning when the securing set screws i8 are rotated.

The inner end of each housing member 20 may be in the form of an annulus 25 receiving a sleeve 1 and provided with an inwardly extended flange 26 engaging the inner end of said sleeve. The

' diameter of the sleeve 1 is less than the inside diameter of the annulus 25, so that said sleeve 1 and said annulus may expand and contract relatively and freely without interference of either with the other.- This construction constitutes means pemiitting the return bend it and the sleeve 1 to be made from the same metal or from metals having approximately the same coeilicient of expansion, while the housing members 29 may be made from a different and less expensive metal having a different coefficient of expansion without the least sacrifice in the efliciency and durability of the device. Adjacent to and extending outwardly from the annulus 25 each housing member is formed with a longitudinal opening 21 through which the ears or lugs 8 and 9 in connection with the sleeves I extend to interlocking connection, as shown and described.

The opening 28 at the inner portion-of each sleeve 1 is concentric with the axis of the tapered bore l2 and receives one end of a tube 29. Accordingly, when the sleeves I and the return bend ll are assembled in connection with each other and with the tubes 29, a continuous passage fromone of said tubes 29 to the other of said tubes 29 is provided.

The sleeves 1 may be attached to the tubes 29 either by rolling or expanding the ends of the tubes within the sleeves by means of a suitable tool to obtain the attachment shown in Fig. 1; or the sleeves may be screwed on the tubes. It is possible to screw the sleeves I on the tubes and to obtain a satisfactory connection when said sleeves and the tubes have the same coeflicient of expansion but, if the coefilcient of expansion of the sleeve is diiierent from that of the tube, a screw threaded connection is not satisfactory because the connection may become loose when there are changes in temperature.

The tubes 29 may be held from substantial spreading apart or moving toward each other by a tie member 30 having openings 3| through which said tubes extend. As shown, the tubes 29 extend through a head 32 having openings 33 of slightly larger diameter than the outside of the tubes. In this assembly, the tie member 30 performs the useful functions indicated.

In assembling and mounting my invention for use, the tie member 30 is placed on the adjacent ends of a pair of adjacent tubes 29 which extend through openings in the head 32. The openings 3| permit the tie member 3ll to slide along the tubes to proper position. The annulus 25 of a housing 20 is then applied about the end of each tube and a sleeve 1 in each annulus 25 is attached to the adjacent end of the tube either by expanding the tube within the sleeve or by screwing the tube in the sleeve. In this position of the sleeves l, the ear or lugs 8 and 9 on the respective sleeves are in overlapping and sidewise abutting relationship, thus preventing substantial relative twisting or lateral movement of the sleeves. The bolt II is then passed through the slots II and secured in this position.

After the sleeves I have been attached to the adjacent ends of adjacent tubes 29, the tapered ends l3 of the return bend it are placed in and against the joint forming seat I 2. The plates 19 are then mounted in position with the parts 2| thereof extending into the openings 23 in the housing members 20. The set screws l8 are then screwed inwardly against the bottoms of the recesses IE 'to apply the pressure necessary to force the tapered ends l3 of the! return bend into and against the joint forming seats l2 and thereby obtain an extremely tight connection and joint. This clamping adjustment of the screws 18 causes the flanges 26 to abut securely against the inner ends of the sleeves I, and the ends l3 of the return bend to be forced into close sealing engagement with the 'seat l2. Should there be slight inequalities in the dimensions of the tapered 'ends l3 or the seats l2 or slight inequalities in the arrangement or location of the ends of the tubes, the necessary tolerance to obtain perfectly tight joints irrespective of these inequalities is obtained by this improved construction and arrangement shown, because neither the sleeves 1 nor the housing members 20 are integrally united. Necessary longitudinal or axial adjustment of the sleeves. I to provide tolerance and compensate for slight inequalities in the arrangement or location of the ends of the tubes is permitted by the slot In.

It must also be apparent that my invention prevents lateral or twisting movement of the sleeves with respect to each other and that there is-no twisting strain exerted against the return bend when said bend is placed and clamped in position. In the case of devices heretofore used, it has occurred'that when the return bends were removed after a still had been in use, it was found that the return bends on being replaced did not assume the same relative positions with respect to the tubes that they occupied before they were removed. By eliminating lateral and twisting movement of the sleeve with respect to each other, this diiliculty is avoided. It has also oc-- curred that the tubes warp and strain the return bends, so that after the return bends have been removed and replaced a number of times in different positions, they are subjected to such strains in different directions that the return bends eventually break or become useless. These twisting actions and strains produce a damaging crystallizing effect on the return bends. My invention completely eliminates these difficulties and prevents the application of twisting strains to the return bends either by the warping of the tubes, or otherwise.

I claim:

1. A return bend fitting comprising a plurality of adjacent sleeves; longitudinally extending spaced tongues carried by said sleeves for interlocking them together to prevent relative lateral and twisting movement therebetween; means for securing said tongues together to permit longitudinal movement of the sleeves relatively of one another; a return bend; a housing about each sleeve; and means for securing said return bend in said housing.

2. A retiu'n bend fitting comprising a plurality of sleeves having longitudinally extending tongues for interlocking said sleeves together to prevent lateral and twisting movement of one sleeve relative to another; means for securing said tongues together to prevent separation of the latter and permitting longitudinal movement relatively between said sleeves; a return bend element; a housing partially surrounding each of said sleeves; a tube secured in each of said sleeves; and means for securing said return bend element in said housing to communicate with said tubes, the ends of said return bend element secured in said sleeves.

3. A return bend fitting comprising a plurality of sleeves having longitudinally extending tongues and grooves for slidably interlocking the same together to permit longitudinal movement only between said sleeves; means through said tongues to prevent separation of the sleeves; a return bend removably secured in said sleeves; a tube secured in each of said sleeves; a housing about each of said tubes and a portion of each of the sleeves and partially surrounding the remaining portion 01 said sleeves and projecting therebeyond; and means removably carried by said housing for securing said return bend in position.

4. A return bend fitting comprising a plurality of sleeves having an interlocking tongue and groove longitudinally tfierebetween to slidably interlock the same together to permit only longitudinal movement between said sleeves; means through said tongue and groove connection to prevent separationof said sleeves; a return bend removably secured in said sleeves; a tube secured in each of said sleeves; a housing surrounding each of said tubes and a portion of each of said sleeves and partially surrounding the remaining portion of said sleeves and projecting beyond the latter, said housings having an inwardly extending flange on their lower ends and against which the sleeves may seat; and means including a removable plate carried by said housings for securing the return bend in position.

5. A return bend fitting comprising a plurality of sleeves provided with longitudinally extending means for slidably interlocking them together and permit only longitudinal movement therebetween; a return bend removably secured in said sleeves; a housing surrounding a portion of each sleeve and projecting therebeyond; and means mounted on each of the housings to engage the return bend !or securing the latter in said sleeves.

6. A return bend fitting comprising a plurality of sleeves having longitudinal tongues and grooves therebetween to slidably interlock said sleeves together to permit longitudinal movement only between the same; means to prevent separation of said sleeves; a return bend; a housing having an inwardly extending flange adjacent one end and provided with a longitudinal opening through its wall thereabove, one of said sleeves positioned in each of said housings; and a plate and screw removably carried by each oi said housings to secure the return bend therein in said sleeves.

7. The combination with a return bend adapted to connect a plurality of tubes; of a fitting therefor comprising tubular elements adapted to be connected to the tubes; housing sections independent of said tubular elements and looselyencircling the latter; detachable means mounted in said sections to engage said return bend; and co-acting portions on said tubular elements that prevent twisting movement between the same but permit a slight relative longitudinal movement between said tubular elements.

8. The combination with a return bend; of a fitting therefor comprising sleeves each engaging one of a plurality of tubes; housing sections surrounding said sleeves; means on said housing sections for holding the return bend in operative relationship with said sleeves; and means at the sides of said sleeves and extending through said housings preventing relative twisting movement between said sleeves but permitting a slight longitudinal movement therebetween. 

